i) Field of the Invention
This invention relates to novel polymers and copolymers and novel monomers which introduce useful characteristics into such polymers and copolymers; in particular the invention is concerned with novel cyano-substituted stilbenes, which provide thermal crosslinking characteristics in polymers and copolymers; cyano-substituted phenanthrenes-containing polymers and copolymers which are high temperature polymers; and coloured phthalocyanine-containing polymers and copolymers for use in charge generation layers in electrophotography, including xerography and in laser printing.
ii) Brief Description of Prior Art
Advanced composite materials are made from combinations of high performance fibers, such as glass, graphite, carbon, silicon carbide or ceramic fibers, arranged in close packed alignment in the polymer as a matrix. Such composite materials provide a combination of strength and modulus superior to that of structural metals and alloys on an equal weight basis. Such composites are, for example, employed in military and commercial aircraft, and space vehicles, as well as in sports equipment, in tennis racquets, shafts for golf clubs and sailboats.
These composite materials are expensive, and so their use is confined to relatively high cost items. On the other hand, even though the raw materials for these advanced composites are expensive, over 70% of the costs associated with such composites result from the processing costs for their manufacture.
In particular, the currently used manufacturing process produce volatiles during curing of the polymer matrix and such volatiles produce voids in the matrix which act as sites for structural failure. In order to minimize void formation during evolution of volatiles, the cure must be carried out over a long period, under reduced pressure and this manufacturing requirement is a major factor in the production cost.
There is thus a continuing need for curable polymers and copolymers.
The most well known curing reaction involving cyano groups is the use of polyacrylonitrile fiber as a precursor in the production of carbon fibers. Heating between 200.degree.-300.degree. C. in air crosslinks the polymer to a form in which it is insoluble in organic solvents, and infusible; and this crosslinked fiber is graphitized at high temperature.
Polymers containing phthalonitrile groups on the ends of the chains can be cured to insoluble resins when heated to elevated temperatures, as described in U.S. Pat. Nos. 5,132,396 and 5,159,054.
Phthalocyanines are known as pigments, dyes or colouring agents, as described in High-Technology Applications of Organic Colorants, Peter Gregory, Plenum Press; for example, their use has been described or proposed in solar cells and in charge generating layers in electrophotography. In these proposals, however, the phthalocyanine colorants are dispersed in a polymeric binder, for example, a polycarbonate.